1/4″ x 1″ x 15″ Aircraft or Tempered Aluminum Bar (7075-T6)
2-Part Epoxy Glue
Table Saw: -or-
Cutting the Reinforcement Channel:
The first thing that you should know is the exact depth and taper that you are planning to give your neck. Usually the neck tapers from the heel to the nut, so we take advantage of that taper with our reinforcement bar as well.
When you have determined the taper, plan on making the bar about 2 – 3 mm less than that amount. The taper on the Ultimate Guitar Building Plans varies from model to model, but generally it runs from about 11mm neck thickness at the nut to 18 mm neck thickness at the heel.
You will want to cut this channel just after you have finished gluing the scarf joint for the guitar head while the neck blank is still squared off. This allows you to run the neck down the fence of a table saw squarely.
Calculate the cutting depth: In the example above, we would have at the nut end: 11 mm – 2 mm = 9 mm. That would be a starting depth of 9 mm and an ending depth of about 18 mm – 2 mm = 16 mm. Take the difference between these two numbers: 16 – 9 = 7 mm.
You now need to secure a 7 mm wood shim under the NUT end of the neck. I usually put just a few dabs of glue on this piece to hold it in place. You can also tack in in place with small brads. Place one on each end (outside the neck width line) and one on either side of the channel (make sure you don’t cut through them and that you don’t penetrate far enough to go through the finished neck coutour).
Now set your table saw blade to 16 mm and cut your channel. You will end up with a channel that tapers gradually from 9 mm at the nut to 16 mm at the opposite end.
Cutting the End Restraint Channels:
I prefer to complete this step after the neck contour is shaped to it’s final dimensions. I do this because I can make actual measurements of the neck. Make a couple of templates of the neck contour. You can use a Contour Gage to make an exact duplicate of the neck cross-section. Do this at the nut and at the point where the neck meets the heel.
Transfer these contours and make your templates. This can be on a sheet of paper if you like. Cut out the template, trace a line at about 4 mm inside the contour template and cut it out. That will be your Restraint Piece shape. Paste this on the T6 Aluminum Bar Stock. Cut out the shapes and that will be your contours for you end pieces.
Cutting The Channels for the Restraints:
This is probably the hardest part of the entire process. If you want to make this your standard installation, I would suggest that you make a jig for this operation. For now just mark the dimensions of width and length on the face of the neck (fretboard side) and cut these channels with a sharp chisel – take it slowly.
Gluing the Aluminum:
Now it is time to glue in the end restrains. Mix up some 2-Part Epoxy Glue and fit the restraining pieces in place. Place the necessary cauls and waxed paper in place and clamp.
After the restraints have dried, cut your neck reinforcement bar to length to that it fits tightly into place between the two restraining pieces. (not so tight you have to hammer it in, but tapping it in place is what I mean)
Mix up your Epoxy and glue this into place as above and you are done. When dry, take the neck to the Stationary Belt Sander and smoothen the gluing/bar surface so they are absolutely flush. Ideally your bar reinforcement will be just slightly below the surface of the wood neck to make sanding more successful.